Nutritional, Energy and Sanitary Aspects of Swine Manure and Carcass Co-digestion

Abstract

Renewable energy can assist the management of the effects of population growth and rapid economic development on the sustainability of animal husbandry. The primary aim of renewable energy is to minimize the use of fossil fuels via the creation of environmentally friendly energy products from depleted fossil fuels. Digesters that treat swine manure are extensively used in treatment systems; and inclusion of swine carcasses can increase the organic loading rate (OLR) thereby improving biogas yield and productivity on farms. However, the characteristics of the components including animal residues, proteins, lipids, remains of undigested feed items, antimicrobial drug residues, pathogenic microorganisms and nutrient contents, are complex and diverse. It is therefore necessary to manage the anaerobic process stability and digestate purification for subsequent use as fertilizer. Efficient methane recovery from residues rich in lipids is difficult because such residues are only slowly biodegradable. Pretreatment can promote solubilization of lipids and accelerate anaerobic digestion, and pretreatments can process the swine carcass before its introduction onto biodigesters. This review presents an overview of the anaerobic digestion of swine manure and carcasses. We analyze the characteristics of these residues, and we identify strategies to enhance biogas yield and process stability. We consider energy potential, co-digestion of swine manure and carcasses, physical, chemical, and biological pretreatment of biomass, sanitary aspects of swine manure and co-digestates and their recycling as fertilizers.

Factors Affecting Gut Microbiome in Daily Diet

“…Dietary guidelines from popular science often suggest high protein intake, especially from animal sources with diverse and enough essential amino acids, to combat muscle atrophy, obesity, weakness, osteoporosis, surgical stress and death rate. However, a proper ratio of protein to carbohydrate, or even a relatively low protein diet, is more recommended because excessive protein promotes the growth of pathogenic microorganisms, inducing a high risk of metabolic-related diseases ( 81 ). Residual nitrogenous compounds not absorbed by the small intestine are transferred to the distal intestine and metabolized by microorganisms in this part.…”

Anaerobic Co-Digestion of Swine Manure and Hydrolyzed Swine Carcasses at Two Different Biodigesters

“…This success is largely attributed to the high buffering capacity and wide variety of nutrients in swine manure, as well as the high content of volatile solids, proteins, and fats from swine mortality waste. However, the ratio between manure and carcasses must be adjusted to prevent the accumulation of free ammonia (FA) (8,9).…”

“…The inclusion of animal carcasses typically alters the characteristics of the digestate, especially the nitrogen concentration, necessitating the monitoring of its properties prior to agricultural use. It is also crucial to consider the usage restrictions in terms of biosafety aspects (9). The use of swine carcasses in anaerobic biodigesters can be an interesting practice for several reasons.…”